rx7tt95

This isn't strictly third gen specific, so feel free to move it to a more appropriate section if there is one.

As a general rule, I replace the tranny/diff fluid once a year. Last year I had the stock Mazda fluid removed (at about 10K miles, and yes, I've only had the car two years) and replaced with Amsoil Synthetic in both the gearbox and the rear differential.

I've been doing a bit of preventive maintenance and decided to replace the fluid again, this time with Royal Purple as I had heard a few bad things about Amsoil.

When the tranny fluid was drained, it resembled caramel in color, a very muddy brown. Inspecting the transmission fluid plug, the magnet on the end had collected quite a large amount of metal shavings (no chunks). The rear diff fluid was actually worse in terms of color, but not as much metal. The Amsoil did not hold up well at all, having been in the car about a year. I do race and I'm sure that had something to do with it. None the less, it's a definite testimonial that Amsoil is not a product I want to use in the future. I cannont compare it to Royal Purple (talk to me in a year!) but I can compare it to Mobil 1 and a few others that I used in various muscle cars (also raced) over the years. I've never seen such degraded fluid coming out of a transmission.

Bottom line, if you're using this product, drain it and fill it with RP, Redline, Mobil 1 or something along those lines.

RX7_Fast_Lane

Thanks for the heads up.

Street King

Yup I use Mobil 1 and I couldnt of asked for more. Thats one thing people pass over ..THE DIFERENTIAL!! I changed all fluids when I recieved my car. Threw some Mobil 1 in there too. Man I love that stuff and so does my car.

Nathan Kwok

I use Neo and have been pretty happy, although I think my tranny is on its way out (2nd and 4th making bearing noise). Interestingly enough after I started hearing the noise I changed the fluid and there was barely any metal on the drain plug. The oil seems to hold up pretty well but my last change interval was very short. When I changed the diff oil for the first time, man, that looked nasty and smelled even worse. Talk about completely black, and this was a car with <40k miles at the time.

rx7xrx7

Did you use the new series 2000 Amsoil tranny fluid because I just put it in my 93 which was grinding slightly in 2nd and 3erd. The shifting is much much better. I am totally pleased with the increase in the smoothness of the shifting. I will change it next year to see what it looks like since I read your results. The fluid I used was blue in color. 75w-90 series 2000. The new stuff.

turbojeff

iTrader: (30)

The color of the oil and amount of "shavings" on the plug doesn't seem like a very good indicator of how the oil held up.

Your trans is used, over time it will wear more and more, every 10K miles will give more shavings than the last 10K miles.

That said I've run Amsoil and Redline MTL for a short time, shifting was better but only when cold. I refilled the trans with standard gear oil and I like it better.

Jeff

GoodfellaFD3S

iTrader: (213)

I know that RP swears by Amsoil. I personally use Mobil1 in the tranny and really like it. Big improvement.

rx7tt95

The Amsoil I had was initially a very light amber color, bordering on clear which sounds like the "old" stuff. Not sure about the new stuff or what the differences are. After seeing the oil drain, the rotary shop doing the work (replacing the tranny's rear seal/fuel filter, turbo drain back filter/downpipe gasket) actually called Royal Purple about becoming a dealer, LOL. They were not amused by the shape of my tranny/diff fluid. They also have great trouble selling Amsoil in our area.

TurboJeff, if I had the time/money, I'd send it out to be analyzed by a qualified chem lab. The oil wasn't "burned" but it also wasn't right and was the worst that I, and the shop which changed the oil had ever seen. I'm just merely giving a head's up to those running it that perhaps they should check it :-) Nothing scientific here! Honestly though, there was a bit too much in the way of metal shavings when the oil was drained. My tranny, hopefully, is perfectly healthy. No grinding. Even though I do race, I lift off the gas fully in between shifts and generally take good care of it. So...draw your own conclusions and do a bit of research if there's any concern using this stuff.

As for the RP (75W-90), shifts are definitely more fluid with less effort. Didn't notice right away upon leaving the shop, but it seemed to get a bit better as the day went on. We'll see how this stuff holds up. It also incorporates friction modifiers for use in plate type rear diffs.
Michel

apneablue

I am running AmsOil right head to toe on the FD and really can't say much right now since I just put it in about 2 months ago...However I run Royal Purple in My R6...and leme tell ya, I run the **** out of that thing and the Purple stuff holds up...But then I change it every 1500miles so I really don't give it a chance to break down...